5D2 outer points fail to lock on many subjects which can be annoying, 5D3 ones tend to lock.

"5D3 ones tend to lock"... True. And they tend to lock accurately. The old 9 points array used to give a me a lock on the outside points, but it far too often turned out to be wrong. Not wrong enough to see on the camera monitor, but wrong enough to dump at the sorting and ranking stage. It didn't take long to only trust the centre point.

i have been under the impression that the primes are not fast auto focusing lenses. i dont have any yet but i have worked with plenty of people who have. i have especially heard the 85mm L is a bit of a dog with AF. i'm on the fence right now about incorporating them into my work but even if i do i cant see myself not continuing to rely on the 24-70 and the 70-200.

i wonder if a more accurate test of the new AF system might be performed using the 70-200mm F2.8L? anyone have more experience that could enlighten us on this matter?

The 85L has a different focusing system than any other Canon lens, and is notoriously slow. No one buys one for fast AF. And primes are known for the fastest AF. Take the 135L, for example.

My wife and I shot a wedding yesterday, we brought two 5DII bodies, and one 5DIII body. I didn't bring out the 5DIII until the reception because I didn't want to use it for the critical stuff until I've spent more time with it. For the reception ( private room inside restaurant ) we were using the 85 f/1.2L II, 35 f/1.5L and 50 f/1.4. I lost many good shots because the 5DIII took 2-3 seconds to focus. I tested focusing in the low light with all the lenses, and the results were similar ( well, the 85 was even slower, because that lens is just slow focusing ). For AF, I had "one shot" selected, and the center point with the 4 surrounding points. I couldn't easily do a side by side because I didn't have two of any one lens, but I did switch lenses between the bodies and played around some. The 5DIII was as slow, or possibly even slower than the 5DII to achieve focus. The amout of natural light in the reception was around ISO1600, f/1.4 and 1/60. Oh, and I had a flash on, putting out that red focus assist as well during all this testing! Anyway, just giving people a heads up on what I experienced, and I've seen some others post the same. I've also seen people post results of miraculous AF improvement with the 5DIII...

FIRST thing you do is disable the red AF assist light. That's what's causing your delay. You shouldn't need to use it at all. (Which is why I think the ST-E controller (new one) doesn't have the light on it).

You shouldn't need AF assist until at the very least ISO6400 - 1/60 - 2.8Remember too, despite realising it you will be moving, your subject will be slightly and yet the AF light is slower and relies on static objects. The 5D3 AF system can AF in full moonlight, you don't need it.

Coming later to this thread, I decided to add a reply here because there is so much good information in the older messages. I hope everyone read all the posts. Well, I should say I am glad I read all the posts because there are good suggestions to try when facing [apparently]slow auto focus on their Mk3's.

...because I am one of them.

I have had some good conversations with Canon. I am a professional photographer who will use the body for paid work when back home from this long personal travel, so I have to sort this out.

I have tried the camera with the lenses I have with me: 85mm f1.8, 24Lf1.4, and the 24-70mm The 24-70 has some kind of problem with focus motor and is going to Canon this morning. But even with the others there were delays. I KNOW this isn't the result of careful testing, just a description of my experience in the moment. I am adding a tile to the mosaic of shared experiences with the 5DMk3. I have been shooting with a 5DMk2 for a while. That body is at home.

I have spent several nights shooting with the 24 and 85 in a dark bar where local musicians get together to jam. I am sometimes pretty close. Not a concert -- the lighting is way lower than stage illumination. Some fluorescent light, too. I plan to use this body at wedding receptions, for example, and the challenge will be similar. I too had delays getting any confirmation of focus, and I was set up to require confirmation before shooting. Perhaps I will try allowing the camera to shoot before confirmation but it seem like a bad idea. I tried switching back to manual focus and it seemed more fluid and quick to get shots! Yikes! I was also practicing constant movement of the chosen focus points to train my without-looking muscle-memory-touch.

So I will keep testing, but because I am 6,000 miles closer to Canon's Virginia repair site I may make them swap out my body. Maybe the new one will do all the same things and I will know what I have to do to adjust. But the OP had a similar experience to mine and although there are some excellent suggestions in the thread (which I just stumbled on this morning) I have to be confident in the body.

Thank, especially, to all those people who contributed their thoughts, suggestions, detailed experience with AF settings, and personal testing.

I have been shooting running events without focus speed issues for normal sports. I even just shot a triathlon and the bikers are flying way faster than a runner and i was able to lock on dead but due to multiple people and having to refocus quick I'd have preferred the 1dm3. For extreme sports i can shoot anything just not muliple quick changes to refocus on diff people at diff distances quickly. If i have time to switch from one person to the next i dont have problems with the focus locking. I just never thought i'd love shooting sports with my next 5d series camera. I love it.

My wife and I shot a wedding yesterday, we brought two 5DII bodies, and one 5DIII body. I didn't bring out the 5DIII until the reception because I didn't want to use it for the critical stuff until I've spent more time with it. For the reception ( private room inside restaurant ) we were using the 85 f/1.2L II, 35 f/1.5L and 50 f/1.4. I lost many good shots because the 5DIII took 2-3 seconds to focus. I tested focusing in the low light with all the lenses, and the results were similar ( well, the 85 was even slower, because that lens is just slow focusing ). For AF, I had "one shot" selected, and the center point with the 4 surrounding points. I couldn't easily do a side by side because I didn't have two of any one lens, but I did switch lenses between the bodies and played around some. The 5DIII was as slow, or possibly even slower than the 5DII to achieve focus. The amout of natural light in the reception was around ISO1600, f/1.4 and 1/60. Oh, and I had a flash on, putting out that red focus assist as well during all this testing! Anyway, just giving people a heads up on what I experienced, and I've seen some others post the same. I've also seen people post results of miraculous AF improvement with the 5DIII...

I can't speak for the other lenses but the 50 1.4 does tend to hunt in low light unless you use just the center point. I have the 70-200 L is and it doesnt like low low light either, but let me say there is nothing bad about that lens!!! It can focus on my Mark III but its a little to slow for anything thats not going to stay put. The dimmer the light the harder it is to focus for any lens. I will say my 24-70 2.8 is a hammer and never ever leaves me disapointed. My 16-35 never ever cries in a corner in bad light either. Some lenses are just better than others in low light it seems

Like the OP, I have the same slow focus issue at weddings. I have shot 5 weddings in the past 4 weeks with the Mk3 and used multiple settings, tried changing focus-release etc. Mk2 -- and even Mk1 -- are faster. Could be the particular body, but my second shooter's experience is the same. Hands down I prefer the Mk3 to the Mk2, but it's focus speed -- not it's accuracy -- leaves much to be desired. With decent light the AF has been rock solid for me, but like the OP at 5 wedding receptions now I've missed moments that I KNOW I would not have with he Mk2. That's frustrating. But, I guess, there is no silver bullet camera out there, and Canon continues to have AF issues even if they've addressed other supposed short-comings.

canon rumors FORUM

SandyP

Not sure what's going on, at all, but in the last few weddings I've shot with the 5D3, it's far faster, far more reliable and far easier to shoot in more AF intensive situations than the 5D2 ever was. And I had the 5D2 since it came out and shot with it at countless weddings. I can finally stop using the center point only.

I haven't had time to really play with my AF settings to really fine tune them for each situations, but I have heard that it can make a big difference to be using it to it's full potential, rather than setting it one way and going from there.

Same here Sandy. It appears as though users are getting mixed results though. I'm not sure the cause of this, but it's interesting that after using the 5D Mk II so much, for me, I noticed the faster AF of the Mk III right away, in lower light. Interesting.